Question

Consider two events with coordinates and in an inertial frame of reference S.
Thecoordinates of these two events in an inertial frame
S'moving to the right with speed relative to frame S are and .

If we assume that the y and z coordinatesare
constant in the two frames, then is the space interval, more commonly known
asdistance, between the events as measured in frame S',
and is the space interval in the frame S. These
twointervals are more commonly written and , respectively. Similarly, is called the time interval between the events
inframe S', and is called the time interval in frame S.
Thesetwo intervals are more commonly written and , respectively.